Detergent composition



Patented Apr. 24, 1945 DETERGENT COMPOSITION Lawrence H. Flett, Hamburg, N. Y., assignor to Allied Chemical & Dye Corporation, a corporation of New York No Drawing. Application September 20, 1941,

Serial No. 411,756

6 Claims.

This invention relates to detergent compositions. It relates more particularly to detergent compositions in the form of solid cakes or similar formed solid masse adapted for use as a substitute for toilet soaps, especially by persons who are allergic to ordinary soaps.

The usual toilet soaps, as ordinarily marketed, are essentially mixtures of the sodium salts of higher fatty acids which, because they are salts of weak acids and strong bases, are easily hydrolyzed in water solution and lead to the presence of free fatty acids and alkali in their aqueous solutions and on the skins of persons using them. Many persons exhibit an allergic reaction to soaps, manifested by a dermatitis or an eczematic condition, which some attribute to the free fatty acids and others regard as a hypersensitivity to alkali. In .addition, persons who are required to wash their hands frequently and persons with delicate skins suffer from the harmful effects of the alkali on the skin.

One class of compounds which, by reason of certain of their advantageous properties, are of value for use as substitutes for ordinary soaps by persons exhibiting an allergic reaction to ordinary of disadvantages. Because of 'the solubility of the soapless detergents, the cakes usually disintegrate rapidly in water; and when rubbed between the hands in the usual washing operation, an excessive amount of the detergent is removed from the cake, resulting in a roughness-and dryness of the hands after washing and in waste of the detergent.

An object of thepresent invention is toprovide a non-allergenic soap substitute for persons who are allergic to the ordinary soaps. More specific objects are to provide a cleansing composition which is non-allergenic to the human skin; which can be manufactured in the form of the usual soapare overcome and a. non-allergenic cleansing agent soaps is the class of non-aromatic organic soapless detergents which are neutral, water-soluble salts of anion-active polar-nonpolar organic derivatives of sulfuric acid having a single higher open-chain hydrocarbon group of 12 to 14 carbon atoms in the nonpolar portion of the molecule. A number of such compounds have been introduced commercially as substitutes for the usual soaps in the textile and related industries by reason of their wetting, emulsifying and cleansing action on textile fibers. They include products containing as the essential cleansing agent alkyl sulfates containing 12 to 14 carbon atoms in the alkyl group, alkyl sulfonates containing 12 to 14 carbon atoms in the alkyl group, sulfates and sulfonates of higher monoalkyl esters of lower monoand polycarboxylic acids containing 12 to 14 car- 'bon atoms in the higher alkyl group and a sulfate or sulfonate group in the carboxylic acid radical or in the esterifying radical, sulfates of polyhydric alcohols (such as glycerin) partially esterified by fatty acids containing 12 to 14 carbon atoms, and the like. The are water-soluble compounds which form substantially neutral aqueous solutions. Further, they do not hydrolyze in the objectionable manner of soaps and, being relatively stable in aqueous solution and for the most part being free from higher fatty acid components, they do not introduce into their aqueous solutions the objectionable alkali and free fatty acids produced by the hydrolysis of ordinary soaps.

While the said soapless detergents can be prepared in the form of solid cakes of the type of ordinary soap cakes, such cakes possess a numberwhich is adapted for personal toilet use in the same manner as ordinary soap cakes by persons showing an allergic reaction to ordinary soaps is provided while avoiding the objectionable properties of cakes of soapless detergents. I have discovered that compositions which are composed essentially of one or more non-aromatic organic soapless detergents. which are neutral, watersoluble salts of anion-active polar-nonpolar organic derivatives of sulfuric acid having a single higher open-chain hydrocarbon group of 12 to 14 carbon atoms, preferably joined to each other in a continuous chain, in intimate mixture with at least an'equal amount of one or more watersoluble, substantially neutral, organic compounds which are non-irritating to the skin, which contain within the molecule, as the essential functional group, the radical ll GNH at least once, and which preferably are nonirritating to mucous membranes, odorless and colorless, possess a, number of advantageous properties' which adapt them fOr use as non-allergenic substitutes for toilet soaps. Thus I have, found,

in accordance with the present invention, that.

into cakes similar in appearance to cakes of toilet soap, and, when used for personal toilet purposes,

forms a suds similarly to soap; and it does not produce the harmful effects upon the skin caused by ordinar soaps.

The non-aromatic organic soapless detergent componentof the compositions of the present invention 'may be any one or a mixture of such compounds which are solid. neutral, water-soluble salts of non-aromatic sulfates or sulfonates containing a single higher open-chain hydrocarbon group of 12 to 14 carbon atoms, preferably joined to each other in a continuous chain. They are preferably compounds which do not decompose to give higher fatty acids under conditions of toilet use. They include salts of the following types of compounds:

A. Open-chain hydrocarbon sulfates and sulfonates derived from aliphatic hydrocarbon, olefines or alcohols containing 12 to 14'carbon atoms. Those which are primary normal (straight-chain) sulfates and sulfonates are preferred. A commercial product of this type containing sodium lauryl sulfate as its essential detergent constituent is sold in the market under the name of Gardinol. Sodium myristyl sulfonate is another compound of this type.

B. Sulfates and sulfonates of higher monoalkyl esters of lower monoand polycarboxylic acids containing 12 to 14 carbon atoms in the higher alkyl group and a sulfate or sulfonate group in the carboxylic acid radical or in the esterifying radical. Lauryl sulfoacetate and disodium monolauryl sulfosuccinate, particularly in the form of commercial products derived from mixtures of alcohols obtained by the hydrogenation of coconut oil (fat), are compounds of this p C. Sulfates and sulfonates of poiyhydric lower alcohol partial esters of fatty acids containing 12 to 14 carbon atoms which contain only one higher fatty acid radical in the molecule. The sodium salt of lauric acid monoester of glycerin sulfate is a compound of this type.

D. sulfates and sulfonates of lower alkyl ethers of aliphatic alcohols containing 12 to 14 carbon atoms. Compounds of the type RO.CH2.CH2.OSO3Na COONa S OaNa is a compound of this type. It can be prepared by reacting equimolar proportions of maleic anhydride and laurylamine (or a commercial laurylamine containing a mixture of higher alkylamines) to produce the monolauryl amide of maleic acid, and. reacting the resulting amide with aqueous sodium sulfite.

The said sulfates and sulfonates are employed in accordance with the present invention in the form of their solid, water-soluble, neutral salts, more particularly the alkali metal (including ammonium) salts. Ordinarily the sodium or potassium salts are employed, the sodium salts being preferred because of their superior detergency.

In particular cases it may be desirable to use the ammonium or magnesium salts in whole or in part. Further, in some cases it may be desirable to employ the mono-, dior triethanolamine salts. As obtained commercially, the non-aromatic soapless detergents employed in accordance with the present invention frequently contain substantial amounts of water-soluble inorganic salts, such as sodium sulfate, sodium chloride, and the like. Such commercial products are useful in accordance with the present invention and in many cases the presence of the inorganic salts assists the deterging action of the soaple'ss detergent. If desired, the soapless detergent may be employed in the salt-free form, however.

The other essential component of the compositions of the present invention may be any one or a mixture of water-soluble, solid organic compounds which are non-irritating to the skin, which contain within the molecule, as the essential functional group, the radical (i. e., the carboacylamido radical) at least once. This class of compounds (herein designated for convenience amido bodies") includes substances which are readily soluble in water as represented by urea, which is soluble to the extent of 120 grams in grams of water at 25 C., substances which are somewhat less readily soluble in water, for example monobutyl urea, which is soluble to the extent of about 45 grams in 100 grams of water at 26 C., and also substances having limited solubility in water, such as dicyandiamide and caffeine which are soluble to the extent of about 2 parts in 100 parts of water at about 25 C. They are substantially neutral, so as to avoid the irritating effect on the skin which is generally produced by highly acid and strongly alkaline substances. Preferably they should be non-irritating to mucous membranes, odorless and colorless. Preferred compounds ofthis type are olyamido derivatives of carbonic acid; i. e., compounds which have the following general formula:

n II in which R, R", R' and R"" each represents hydrogen or the same or different organic radicals, and X represents 0 or NH. Examples of such compounds which I have found are well adapted for the purposes of the present invention are:

Urea (carbamide) I HzN. .NH:

Monobutyl urea II C HeNH-C .NHz

found to be satisfactory is to grind the components together, if desired with the addition of a small amount of water or alcohol, and press the' resulting mixture into formed solid masses, such as cakes or bars similar to the usual soap cakes.

Another method, especially useful in the case of alkyl ureas such as monobutyl urea. and dibutyl urea, involves melting the alkyl urea, mixing the soapless detergent with the molten alkyl urea and placing the resulting mixture in molds where they are cooled.

The amounts of soapless detergent and amido body employed in preparing the compositions of the present invention are'variable, depending upon a number of factors. One important factor is the ease of solubility in water of the amido body; another is the hygroscopicity of the result-. ing mixtures. In general, an amount by weight of the amido body is employed at least equal to, and preferably a multiple of, the amount by weight of the soapless detergent (on the basis solely of the sulfuric acid derivative containing 12 to 14 carbon atoms in a higher alkyl group in the soapless detergent; that is, exclusive of other substances which may be present in the soapless detergent in commercial form, such as small amounts of sulfuric acid derivatives of higher and/or lower alkyl compounds and/or inorganic salts).-

When the amido body is relatively easily soluble in 'water (as in the case of urea), the amount of soapless detergent employed is preferably the least amount necessary to give the desired cleansing and sudsing properties to the composition. In that case the amido body functions in part as a diluent for the soapless detergent. Ordinarily at least one part of soapless detergent is employed per 100 parts'by weight of mixture of soapless detergent and amido body of the urea type (exclusive of other substances which may be present). Preferably-the amount of soapless detergent employed should not exceed one-tenth of the. weight of the readily soluble amido body (on the basis of the sulfuric acid derivative alone); and, for the production of cakes of the compositions of the present invention for use as soap substitutes, a lower proportion of soapless detergent to amido body of the type of urea is preferably employed, owing to the fact that watersoluble soapless detergents of the type employed in accordance with the present invention, when mixed with amido bodies of the type of urea, produce a physical effect which results in an increased absorption of atmospheric moisture by their mixtures. lauryl sulfoacetate and urea, the preferred amounts of sodium lauryl sulfoacetate are about 3 to 5 parts by weight per 100 parts of mixture of the sulfoacetate and urea.

When the amido body is not readily soluble in water, as in the case of N-N'-di-n-butylurea, or dicyandiamide, the amount of soapless detergent preferably employed is larger. This is because the amido body in the mixture serves to protect the particles of the soapless detergent and K prevent them from going into solution or being removed by rubbing of the cake of the composition between the hands when the composition is used; only the exposed particles of soapless detergent being dissolved. In such cases an amount of soapless detergent as high as 50 parts per 100 parts by weight of the mixture of pure soapless detergent and amido body may be employed. Preferably an amount of dibutyl urea varying from 60 parts to 75 parts per 100 parts of mixture of soapless detergent and N-N'-di-n-buty1 urea is employed. When using dicyandiamide, it is preferred to use 75 to parts of the same per parts of mixture of soapless detergent and dicyandianiide.

The invention will be illustrated by the following specific examples in which the parts are by weight. Commercial sodium lauryl sulfoacetate, as employed in certain of the examples, was prepared by esterifying chlorac'etic acid with commercial lauryl alcohol derived from coconut oil and reacting the resulting ester with sodium sulfite. In addition to sodium lauryl sulfoacetate and sodium myristyl sulfoacetate, it contained about 12 per cent of higher and lower alkyl sulfoacet-ates; it also contained approximately 30 per cent of its weight of inorganic salts chiefly sodium chloride. Urea, as employed in certain of the examples, was micropulverized to a size such that at least 95% thereof passed a 200 mesh screen before being used.

Example 1.20 parts of commercial sodium lauryl sulfoacetate were ground in a mortar with parts of crystalline urea and 4.8 parts of commercial lauryl alcohol. When thoroughly mixed, the ground mixtur; was formed, at room temperature and under apressure of 10,000 lbs. per square inch, into small circular cakes each of which weighed about-25 grams, had a thickness of about inch and a. diameter of 1 inches.

In the following examples, similar cakes hav ing the following composition were prepared as described above from the following components.

Emample 2 Parts Commercial sodium lauryl sulfoacetate 5 Urea 95 This composition is especially valuable for use as a substitute for ordinary soaps by persons who are allergic to ordinary soaps. Although the amount of sodium lauryl sulfoacetate present in the cake is small, the composition effects a sub- Thus, in the case of sodium action toward harmful organisms. The composition also has a healing efl'ect on rough, chapped and broken skin. In view of the ready availabilityof urea and its relatively low cost, the compositions area easily produced economically.

Example 3 Parts Commercial sodium lauryl sulfoacetate Urea 85 Phthalimide The phthalimide renders the cake more resistant to disintegration on prolonged contact with wa-' ter.

Example 4 Parts Commercial sodium lauryl sulfoacetate Dicyandiamide 75 Example 5 I Parts Gardlnol WA Conc. (commercial sodium lauryl sulfate of low inorganic salt content) 5 Urea 95 Example 6 Commercial sodium lauryl sulfoacetate 5 Guanidine carbonate 95 Example 7 Commercial sodium lauryl sulfoacetate 10 Guanidine carbonate 90 Example 8 Commercial sodium lauryl sulfoacetate 5 Urea 85 Confectioners sugar 10 Example 9 Disodium salt of monolauryl amide of sulfosuccinic acid 5 Urea 94 Lauryl alcohol 1 Example 10 Commercial sodium lauryl sulfoacetate 50 N-N'-di-n-butyl urea 50 Example 11 Commercial sodium lauryl sulfoacetate Cafleine 65 Example 12.-95 parts of a mixture of equal parts by weight of N-mono-n-butyl urea and N-N-di-n-butyl urea were fused by heating to about 95 C. 5 parts of commercial lauryl sulfoacetate were dissolved in the molten mixture with stirring. The resulting mixture was cast into cakes by pouring into a mold and cooling. A cake of distinctive waxy appearance was obtained.

It will be realized by those skilled in the art that the invention is not limited to the above examples and that changes can be made without departingfrom the scope of the invention, Thus instead of the specific soapless detergents and amido compounds employed in the above examples, others of the soapless detergents and amido compounds herein disclosed may be substituted in the same amounts.

Instead of a single soapless detergent, a mixture of two or more may be employed. Further, as illustrated in certain of the examples, a mixture of two or more of the amido compounds may 7 referred to, it is intended that such mixtures.

shall also be included.

The compositions of the present invention flu thermore are not limited to those consisting solely of the soapless detergent and amido compound but as above indicated, the compositions may also contain minor amounts of other innocuous non-detergent materials; such as inorganic salts, therapeutic agents, antiseptic agents, coloring matter, perfume, and the like. Preferably such additional substances should not be allergenic. Inorganic salts may be carried into the compositions of the present invention by the use of commercial Iorms oi. soapless detergents which usually contain them. Additional diluents 01' a nondetergent character are sugar, starch, methyl cellulose and mild abrasives (for example, clay). If desired, small amounts of higher alcohols (as for example lauryl alcohol) may be included as supplementary binder so as to obtain a more coherent cake on molding. Ordinarily such supplementary binder is not required inasmuch as the compositions herein disclosed can be easily molded by pressure into cakes which simulate ordinary soap in appearance.

To persons who are allergic to soap, the compositions of the present invention are especially useful as harmless and non-irritating detergents for personal toilet use. The compositions are excellent cleaning agents for removing dirt and soil; they produce cleansing and sudsing similarly to soap, and they are not precipitated by hard water.

I claim:

1. A detergent composition in cake form adapted for toilet purposes and possessing cleansing and sudsing properties similarly to ordinary soap,

comprising as its essential components a solid, neutral, water-soluble salt of an alkyl sulfoacetate having an open-chain hydrocarbon group of 12 to 14 carbon atoms, in intimate mixture with a solid, water soluble amido body selected from the group consisting of urea, monobutyl urea, dibutyl urea, phenyl urea, acetyl methyl urea, ethyl carbamate, succinamide, phthalimide, caffeine, dicyandiamide and guanidine carbonate, the amount of the salt of the alkyl sulfoacetate not exceeding one-tenth of the weight of the amido body.

2. A detergent composition in cake form adapted for toilet purposes and possessing cleansing and sudsing properties similarly to ordinary soap, comprising at its essential components a sodium salt of a higher alkyl sulfoacetate having 12 to 14 carbon atoms in a normal open-chain hydrocarbon group, in intimate mixture with a solid, water-soluble amido body selected from the group consisting of urea, monobutyl urea, dibutyl urea, phenyl urea, acetyl methyl urea, ethyl carbamate, succinamide, phthalimide, cafieine, dicyandiamide and guanidine carbonate, the amount of the salt of the alkyl sulfoacetate not exceeding one-tenth of the weight of the amido body.

3. A detergent composition in cake form adapted for toilet purposes and possessing cleansing and sudsing properties similarly to ordinary soap, comprising as its essential components an alkali metal salt of a higher alkyl sulfoacetate having 12 to 14 carbon atoms in a normal open-chain hydrocarbon group, in intimate mixture with urea, the amount of the salt of the alkyl sulfoacetate not exceeding one-tenth of the Weight of the urea.

4. A detergent composition in cake form adapted for toilet purposes and possessing cleansing and sudsing properties similarly to ordinary soap, comprising as its essential components a sodium salt of a higher alkyl sulfoacetate having 12 to 14 carbon atoms in a normal open-chain hydrocarbon group, in intimate mixture with urea, the amount of the salt ofthe alkyl suli'oacetate not exceeding one-tenth of the weight of the urea.

5. A detergent composition in cake form adapted for toilet purposes and possessing cleansing and sudsing properties similarly to ordinary soap, comprising as its essential components a sodium salt of a higher alkyl sulfoacetatehaving 12 to 14 carbon atoms in an open-chain hydrocarbon group, in intimate mixture with urea, the amount of the salt of the alkyl sulfoacetate being 3 to 5 parts by weight per 100 parts of its mixture with urea.

6. A detergent composition in cake form adapted for toilet purposes and possessing cleansing and sudsing properties similarly to ordinary soap, comprising as its essential components 5 parts by weight of commercial sodium lauryl sulfoacetate in intimate mixture with 95 parts by weight of urea.

LAWRENCE H. FLE'IT. 

